Producing a fermented food from vegetable raw materials by microbial processes has long been known. In East Asia, a fermentation of vegetable raw materials has developed in which seasoning sauces are produced from soya beans (protein source) and wheat (carbohydrate source). These soy sauces are fermented in a multistage fermentation process and, including a maturation phase, the process takes up to 6 months.
The process includes a so-called solid fermentation in which a microbial starter culture is cultured on the substrate (koji phase). In this case, the fungus used, Aspergillus oryzae or sojae, produces a broad spectrum of hydrolytic enzymes which are able to digest the protein and carbohydrate-rich substrate. This digestion then proceeds in a liquid phase, which is obtained after mashing the koji in a brine solution.
For this purpose, starter cultures (e.g., osmotolerant yeasts or lactic acid formers) are sometimes added. In the further course of the process, a combined alcoholic and lactic acid fermentation takes place with subsequent maturation, in which the typical flavor profile of the soy sauce is produced.
Application of the soy sauce technology to animal raw materials has only been described occasionally, e.g., in Motai, et al., U.S. Pat. No. 4,684,527, Noda, et al., U.S. Pat. No. 4,115,591 and Akao, et al., U.S. Pat. No. 4,587,127. Nakamura et al., Japanese Journal Zootech. Sci. 56: 851-859 (1985), added a koji starter to veal and defatted beef, which were then fermented in salt brine.
The reason for the rarely described use of meat as a fermentation raw material is probably that animal protein alone is not a good substrate for the starter fungus. In addition, animal material is highly perishable, and the formation of components which are of toxicological concern must be expected. Acidifying the raw material in advance, for example, offers protection against a risk of infection in this case. This is described in Tanaka, Japanese Patent Abstract 58111660 by adding acetic acid to the animal protein source "fish." Animal protein is also difficult to ferment since it contains very little fermentable carbohydrates, but instead, inter alia, contains more highly perishable fat.
A simple variant of the meat fermentation is protein autolysis, which is carried out in the fermentation of fish in a salt-containing medium. In this case, no defined starters or enzymes are customarily added, but the substrate (fresh sea fish) is subjected to a natural fermentation and digested with the endogenous proteolytic enzymes. Products produced in this manner are found in East Asia. Chae, et al. describe, in the Abstract of Korean J. Food Sci. 21(5): 639-648 (1989), the acceleration of the production of a fish sauce by addition of koji (as enzyme source).
In order to ferment a raw material, it is conventionally broken down in a suitable manner. For this purpose, roasting, steaming or puffing (extruding) the raw materials is conventionally carried out as in Noda, et al., U.S. Pat. No. 4,115,591.
Although seasoning sauces based on soy sauce technology having a variety of flavors are known, there is still a need for seasoning sauces having novel flavors. In particular, there are currently no seasoning sauces having a full meaty to grilled flavor.
An object therefore underlying the invention is to develop a novel seasoning sauce based on soy sauce technology, which has a novel, full, in particular meaty/grilled, flavor.